Sulfuric acid functionalized magnetic Fe3O4 nanoparticles (MNPs-SO3H) efficiently catalyze one-pot multicomponent condensation of beta-naphthol with aromatic and aliphatic aldehydes and amide derivatives under solvent-free conditions to afford the corresponding amidoalkyl naphthols in excellent yields and in very short reaction times. High catalytic activity and ease of recovery using an external magnetic field are additional eco-friendly attributes of this catalytic system. (C) 2013 Elsevier B.V. All rights reserved.